Throwaway makes a very valid point that crime per areas isn't very useful. But even beyond that the map is also confusing because for the lower elevations it shows both lower areas AND higher area crime incidents. Then as it goes higher, it just shows the higher ones. In other words, it should really show an outer ring for the lowest elevation (since that's where the lower areas are) and then a smaller ring, etc. Only the highest areas would not have a hole in the center (most likely).

Think of elevation maps and how you would select out one range of elevation at a time - you'd end up with donut like rings. You wouldn't mark an area as 500 feet and show all the rings for 500 feet and up. Doing this makes it seem like there are far more crimes than actual for the lower levels.